10
Anderson Greenwood
SerieS 95 Pilot oPerated Safety relief ValVeS
InstallatIon and MaIntenance InstructIons
7 VAlVe diAGnosis Guide
problem
causes
Valve does not close on start-up with
little or no cargo tank pressure
(refer to figure 1)
Main valve piston in lift position, pressurize dome through
field test handvalve (0.5 to 1.0 kp/cm
2
) to close piston.
Valve opens at a pressure below
nameplate set pressure
Set pressure incorrect
auxiliary setter device incorrect one for valve.
auxiliary setter device not screwed down all the way.
Pilot sense diaphragm leaks. Check for gas flow
through pilot spring bonnet vent.
Backflow preventer check valve leaks. (item 15, figure 2)
Check for gas flow at discharge tube to main valve outlet.
No gas flow should be detected.
Valve opens at correct pressure but
does not close
Pilot not sensing correct tank pressure
Check valve in tank pressure sense line (figure 1) restricted.
filter screen in pilot or small orifices in pilot restricted.
iMportAnt
In an emergency, main valve can be closed by pressurizing dome
(top of piston) through close tee (Item 13, Figure 2) remove plug
(item 18) and apply pressure equal to tank pressure.
8 repAir kits
Main valve size
soft goods kit part number
Bolt kit part number
2 x 3
04.4744.810
04.4744.330
3 x 4
04.4744.804
04.4744.331
4 x 6
04.4744.834
04.4744.332
6 x 8
04.4744.835
04.4744.333
Pilot
04.4744.025
04.4744.333
Backflow preventer (diaphragm)
04.4744.781
04.4744.335
Check valve (ball check)
04.4744.782
None
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